1. Field of the Invention
The present invention relates to a system and method of affixing geomembrane to concrete. Specifically, the present disclosure relates to a system and method of utilizing an affixing member to affix geomembrane to concrete slabs used in the construction industry. The geomembranes are utilized for retarding vapor from entering a building from underneath the concrete slab of a building's foundation.
2. Description of the Related Art
A geomembrane is a low permeability synthetic membrane liner or barrier used to prevent the transmission of fluid or gas into a structure that is in contact with the ground. Since concrete is porous, it fails to prevent the transmission of gaseous contaminants into a structure on its own. Thus, geomembranes are used in the construction of buildings to prevent the transmission of water vapor and other contaminants from entering into the building through a concrete foundation that is in contact or in proximity to the ground. Geomembranes are often constructed of polymeric films in sheet form and, in particular, are often times constructed out of polyethylene films. Geomembranes used for preventing vapor transmission through a concrete foundation are often referred to as vapor barriers or vapor retarders.
For a building foundation requiring a vapor barrier or vapor retarder, more than one sheet of geomembrane is typically required to cover the entire area of the building's foundation. As a result, geomembrane sheets commonly are laid adjacent to each other to cover the entire area of the foundation. The individual sheets are typically overlapped and joined to each other with the use of seaming tape. Typical seaming tape adheres the geomembrane sheets to each other but fails to provide any adhesion to the concrete slab of the foundation. Furthermore, the typical polymeric film used as a geomembrane fails to adhere to the concrete slab and may only be held in place by the supporting substrate of the construction site, such as the ground.
Building designers are increasingly concerned that geomembranes may not adequately be held in place against a concrete slab of a building's foundation as the ground or other supporting substrate of the foundation shifts over time. Additionally, buildings are increasingly being constructed with the use of temporary support platforms in regions with expansive soils. The temporary support platforms are used to create space between concrete foundations and expansive soils. The temporary support platforms are laid upon the ground prior to the pouring of concrete. Once the concrete hardens, the temporary support platforms gradually absorb moisture, lose strength, and deteriorate, leaving space between the ground and the concrete slab. The concrete remains supported by piers or other structural supports. Typically, a geomembrane is placed on the temporary support platforms prior to pouring the concrete. However, once the temporary support platforms deteriorate, the sheeting may not be adequately held in place against the concrete slab. An improved system and method is required to hold the geomembrane in contact with the concrete slab without support from the underlying substrate.
An example of a method of adhering a geomembrane to concrete is disclosed in U.S. Pat. No. 8,608,883 B2 (the '883 patent) entitled “Adherent Layer.” The '883 Patent discloses an “adherent layer” that has a substrate, a first adhesive layer applied to the top of the substrate, a second adhesive layer applied to a bottom of the substrate, and a textured layer applied to the top of the substrate and over the first adhesive layer. The '883 patent further discloses that this adherent layer can be attached to a geomembrane acting as a vapor barrier and concrete can then be poured on to the adherent layer. According to the disclosure, a mechanical bond is formed between the concrete slab and the textured layer of the adherent layer, adhering the geomembrane to the concrete slab. However, in the '883 patent, an adhesive is required to adhere the textured layer to the tape substrate. Therefore, there is an increased risk that the geomembrane will not remain adhered to the concrete slab if the adhesive bond fails.
U.S. Pat. No. 7,686,903 B2 (the '903 patent) provides an example of affixing a geomembrane to concrete slabs and other building structures. The '903 patent discloses a composite membrane with a layer of rubberized asphalt, a plastic film layer, and a layer of nonwoven geotextile. The nonwoven geotextile forms a mechanical bond between the membrane and concrete when the concrete is formed on the membrane. The thickness of the entire membrane can range from about 30 to 95 mils. This disclosed geomembrane may be thicker than desired for certain applications and may not be a cost effective solution for all applications.
In view of the foregoing, it is desired to provide a cost effective solution that addresses the need for affixing a geomembrane to a concrete slab and provides an improved bond.